Vertical fire-tube boiler



E 1 April 19 927 o. s. BowMAN VERTICAL FIRE TUBE BoILEE Filed oct.

2 Sheets-Shea?l l INVENTOR ZZ Ver Bow/77a?? ATTORNEY 1927. April 19" o. s. BowMAN VERTICAL FIRE T U BE BOILER Filed oct. 4, 192e 2 sheets-'sheet 2 ATTORNEY' Patented Apr. 19, 1927.

'l UNITED STATES OLIVER S. BOWMAN, OF COLORADO SPRINGS, COLORA-DO.

VERTICAL FIRE-TUBE BOILEB.

Application led October 4,

My invention'relates to vertical fire tube j boilers and my object isto provide a boiler of increased eiiicency of'this type, comprising means for receiving fuel by gravity, and

means for utilizing-its own heat to extract the moisture and more or less of the smoke producing volatile matter from its own` fuel.

Other objects will appear as the description progresses. lo Figure 1 represents a vertical cross section of the boiler along the line A-A in Fig.'2; Fig. 2, a sectional plan view along the line C-e-C in Fig. 1; Fig. 3, a plan view of the movable damper; and Fig. 4, an enlarged fragmentary plan viewshowing the,

annular damper in place.

Although I show the preferred embodiment of my invention, I do not thereby limit v myself to the precise .construction shown, but

wish it understood that various changes in the details of construction may be made within the scope of the claims.

The fire box A, comprising concentric shells 1 and 2 spaced to form a water jacket 3, has an upper rear oblique section 4 with a conduitl 5 therein which is controlled by a sliding damper 6. A fire door 7 and an ash door 8 are mounted on the front of said lire box. A drain pipe 9, controlled by valve 10, communicates with water jacket y3.

A fixed conical grate, mounted in said lire box, is surrounded at the base by a movable annular grate 14.` The conical grate, comprising sectors 11 provided with openings 12, is supported at the apex by stan-dard 13. An arm C, extending horizontally from each sector 11 andresting upon annular pipe 55 hereafter described supports said annular grate 14. An operating lever D is fixed tov annular grate 14 by bolts 14a.

. A main shell 15 has fixed therein an upper tube sheet 16 positioned to form an upper smoke chamber 17. A removable cap 18, having a central hole therethrough, is mounted on shell 15.

A divided lower tube sheet comprises a minor segment 19, the are of which is fixed to the rear of main shell 15, and a major segment 20 mounted on the .inner shell 2 of lire box A.

A Continuous insulating wall B, conforming to an arc of a circle at the front and sides and to a chord at the back, is vertically disposed within said main shell 15 and spaced therefrom. This insulating wall B comprises concentric shells 21 and 22, con- 1926. Serial N0. 139,419.

nected at the top and insulating material 23 therebetween. Outer shell 21 is secured to the chord of minor segment 19 of said lower tube sheet and to main shell 15. Inner shell 22 is mounted on outer shell 1 'of fire box A. A removable band 24 extendsaround main shell 15 and outer shell 1 of fire box A and is held in position by bolts 25.

A lower smoke ,chamber 26 is formed by minor segment 19 of the lower tube sheet, the oblique section 4 of the fire box A, and band 24.

An insulated shell 29 has its ends fixed in upper tube sheet 16 and in the major segment 2O of the lower tube'sheet. A conduit 30, having a flange 31 with avplurality of holes 32 therein, is disposed in insulated shell 29 and spaced therefrom to form a channel 33. An annular damper 34, having a plurality of holes 35 therein, is supported movably on iange 31. A shell 36 of refractory material is-ixed to the lower end of conduit 30.

. A horizontal pipe communicateswith lower smoke chamber 26. A vertical stack 38, with damper 39 therein, is mounted on horizontal pipe 37 and has an ell 40, with damper 41 therein, communicating with upper smoke chamber 17. A suction blower 42 is in communication with horizontal pipe 37. A vertical pipe 43, with damper 44 therein, connects the outlet of blower 42 withstack 38.

f A fuel intake 45 is mounted in conduit 30 and spaced therefrom to form an annular chamber 46. A reservoir 47 is provided with an outlet pipe 48 controlled by valve 49. A pipe 50, having a horizontal and a vertical section, controlled by valve 51, leads from chamber 46 to reservoir 47 and has water jacket 52. The water jacket 52 has an intake pipe 53 and a drain pipe 53a' controlled by valve 54. j I

An annular pipe 55 having perforations 56, is disposed on lugs 55, supports arms C of conical grate sectors 14, and communicates with the outlet of blower 57 via pipe 58; the intake of said blower 57 communicating with reservoir 47 via pipe 59. Pipe 58 is provided with valves 60 and 61.

A steam outlet pipe 62 is fixed in upper tube sheet 16 and extends through shell 15.

A feed water pipe 74 enters ls'hell 15 at the bottom and is provided with valve 75.

Drain pipes 76 pass through the top of wall B, extending downward within.

A return water'pipe 63, for use when operating as a steam heating plant, enters main shell 15 at thel bottom and is'provided with check valve 64 and with control valve 65. Pipe 63 communicates with steam outlet pipe 62 via pipe 66 which is controlled by valve 67 and is provided with a drain pipe 68 controlled by valve 69.

Water gage 70 communicates with water chamber 71 inside insulating wall B and water gage 72 communicates with water chamber 73 outside said insulating wall.

Feed water enters the boiler through pipe 74 and Hows through drain pipes 76 in wall B, within which any desired water level may be maintained by the usual means. If operated as a steam heating plant, the condensation is returned through pipe 63, check valve 64 preventing back flow. Assuming an inflow equal to the evaporation, the outer water level will remain at the end of drain pipe 76 in the top of wall B.

Fuel is delivered by gravity from the bin (not indicated) via intake 45 through conduit 30 onto the grates. .Ashes escape through annular grate 14, which is actuated by lever D. The gases of combustion pass upward through tubes 27 into upper smoke chamber 17, downward through tubes 28 into lower smokechamber 26, out through pipe 37 and upward through stack 38. draft is desired, damper-39 is closed and damper 44 opened, the gases then passing,

from pipe 37 into blower 42, thence through pipe 43 into stack 38,. By opening damper 4l and closin dampers 39 and 44, the gases pass direct y from upper smoke chamber 17 into stack 38.

. By closing the drafts into fire box A and damper 41 and opening dampers 6 and 39 or 44, a downward draft results through tubes 27 into fire box A, thence through conduit 5 into lower smoke chamber 26 and into stack 38; which permits the removal of cap 18 and the cleaning of the tubes from above without drawing the tire.

When damper 34 is open a portion of the gases of combustion pass upward through channel 33 into smoke chamber 17 heating the fuel in conduit 30 and vaporizing its moisture and much or all of itsvolatile content. The vapors are drawn from chamber 46 through water j acketed pipe 50 into reservoir 47 by suction blower 57, which forces the fixed gases through pipes 58 and 55 and thence out through openings 56; the passage of the gases upward through the fire effecting complete combustion. The water and oils, condensed by the passage ofthe vapors through pipe 50, may be drawn from reservoir 47 through pipe 48.

The divided lower tube sheet permits the free circulation ofthe water from the water jacket 3 upward into the boiler proper, and permits a difference in expansion of the up- If an induced draft and down-draft tubes, the latter being surrounded by water of a much lower mean temperature than the former.

All of the water within insulating wall B necessarily has the temperature of its pressure. The water outside wall B has the temperature of its pressure at the top, where it is in contact with the steam, the temperature gradually diminishing downward to the bottom, where the temperature of the incoming feed water prevails; due to the fact that the movement of the partly cooled gases through down-draft tubes 28 is counter to the upward movement of the water. The insulating material within insulating wall B prevents passage of heat from the water within to the water without.

By passing the water through pipes 76,

instead of permitting it to flow over wall B,

wet steam may be avoided.

A boiler of this design, according to tests made by the engineering department of Colorado College during a seven hour run, with an average pressure of 20 lbs., an average fire box temperature of 1700 degrees F. and an average feed water temperature of 60 degrees F., indicated an average stack temperature of 115% degrees F and an average outside shell temperature of 129 degrees F.

With the low stack temperature attained by this boiler, coals having a high moisture content must be dried before reaching the fire box to prevent stack condensation. I

' have, therefore, provided a boiler comprising integral means whereby its own heat is used to extract the moisture from the coal before it reaches the'ire.

I claim:

1. In a vertical return-draft fire tube boiler, in combination, a main shell; a fire box, comprising concentric shells, positioned below said main shell; a lower tube sheet, divided into minor segment, the arc of which is fixed to the rear of said main shell, and a major segment mounted on the inner shell of said fire box; a continuous insulating wall, conforming. to an arc at the front and to a chord of a circle at the back, vertically disposed within said main shell and spaced therefrom, said wall comprising concentric shells connected at .the top and insulating material there-between, the outer shell being secured to the chord of the minor segment of said lower tube K sheet and to the bottom of said main shell, and the inner shell mounted on the outer shell of said lire box.

2. In a vertical fire tube boiler, the combination of a fire box, comprising concentric shells spaced to form a water jacket, having an upper rear oblique section; a main shell having fixed therein an upper tube sheet ositioned to `form an upper smoke cham er; a divided lower tube sheet Y ment of sai-d lower tube sheet, and

an upper rear oblique section; a

.lower tube sheet and to the bottom of said main shell, and the inner shell mounted` on the outer shell of said fire box; drain pipes through said insulating wall extending 1nward and downward; a lower smoke chamb-er between the minor segment of said lower tube sheet and the oblique section of said fire box; updraft tubes fixed in saidupper tube sheet andy said major segment of said lower tube sheet, and down-draft tubes fixed in 'said upper tube sheet and said minor segment of said lower tube sheet;.a

' horizontal pipe communicating with said lower smoke chamber; a vertical stack, mounted on said horizontal pipe and having an ell with a damper therein, in communication with said upper smoke chamber.

.3. In a vertical fire tube boiler, the com bination of a fire box, comprising concentric shells spaced to vform a water jacket having an upper rear oblique section; a main shell having fixed therein an upper tube sheet position-ed to 'form an upper smoke chamber; a divided lower tube sheet comprising a minor segment the are of which is fixedto the rear of said main shell, and a major segment mounted on the inner shell of said lire box; a continuous insulating wall, conforming to an arc of a circle at the front and sides and to a chord at the back, vertically disposed within said main shell and spaced therefrom, said wall comprising concentric shells connected at the top and insulating material therebetween, the outer shell thereof being secured to the `chord of the mi'nor segment of said lower tube sheet and to the bottom of said mam shell, and the inner shell mounted on the outer shell of said fire box; a lowerl smoke chamber between the minor segment of said lower tube sheet and the oblique section of said fire box; and up-draft tubes fixed in said upper tube sheet and said major segdown draft tubes fixed in the upper tube sheet and said minor segment of said lower tube sheet.

In a vertical fire tube boiler, the combination of Ia fire box, comprising concentric shells spaced to form a water jacket, having main shell having fixed therein an upper .tube sheet positioned to form an upper smoke chamthrough said insulating wall ber; a divided lower tube sheet comprising a minor segment, the arc of which is fixed to the rear of said main shell, and a major segment mounted on the inner shell of said fire box; a Icontinuous insulating wall conforming to an arc of a circle at the front and sides and to a chord at the back, vertically disposed within said main shell and spaced therefrom, said insulating Wall com-. prising concentric shells connected at the top and insulating material. therebetween, the outer shell thereof being secured to the chord of the minor segment'of said lower tube sheet and to the bottom of said main shell, and the inner shell mounted on the outer shell of said irebox, drain pipes extendino' inward and downward; a lower smoke chamber between the' minor segment of said lower tube sheet and the oblique section of said fire box; up--draft tubes fixed in said upper tube sheet and said major segment of said lower tube sheet, and down-draft tubes fixed in said upper tube sheet'and said minor segment of said lower tube sheet; a horizontal pipe communicating with said lower smoke chamber; a vertical stack, mounted on said horizontal pipe and having an ell with a damper therein, in communication with said upper smoke chamber; a suction blower in communication with said horizontal pipe; and a vertical pipe connecting said blower andV said vertical stack.

5. In a vertical fire tube boiler, the combination of a fire box, comprising concentric shells spaced to form a water jacket, having an upper rear oblique section; a damper-controlled conduit through said oblique section; a main `shell having fixed therein an upper tube sheet positioned to form an upper smoke chamber; a removable cap mounted on said shell; a divided lower tube sheet comprising a minor segment, the arc of which is fixed to the rear of said main shell, and a major segment mounted on the inner shell of said fire box; a continuous insulating wall conforming to an arc of 'a circle at the front and sides and to chord. at the back, vertically disposed within said main shell and spaced therefrom, said insulating wall comprising concentric shells connected at the top and insulating material therebetween, the outer shell thereof being secured to the chord of the minor segment of said lower tube sheet and to the bottom of said main shell, and the inner shell mounted on the outer shell of said fire box; drain pipes insulating wall, a lower smoke chamber bctween the minor segment of said lower tube sheet and the oblique section of said fire box-t; up-draft sheet-and saidlmajor segment of said 'lower tube sheet, and down-draft tubes fixed in saidv upper tubesheet and said minor seuthro'u'gh said tubes fixed in said upper tube 'ment of said lower tube sheet; a horizontal A *ends fixed pipe communicating with said lower smoke chamber; a vertical stack, mounted on said horizontal pipe and having an ell with a damper therein, in communication with said uppersmoke chamber; a suction blower in communication with said horizontal pipe, and a Vertical pipe connecting said blower and said vertical stack.

6. In a vertical fire tube boiler, the combination of a fire box, comprising concentric shells spaced to form a water jacket, having an upper rear oblique section; a main shell having fixed therein an upper tube sheet positioned to form an upper smoke chamber; a divided lower tube `sheet comprising a minor segment, the are of which 1s fixed to the rear of said main shell, and a major segment mounted on the innershell of said re box; a continuous insulating wall, conforming to an arc of a circle at the front and sides and to a chord atv the back, vertically disposed within said main shell and spaced therefrom, said insulating wall comprising concentric shells with insulating material therebetween, the outer shell being secured to the chord of the minor segment of said lower tube sheet and to the bottom of said main shell, and the inner shell thereof mounted on the outer shell of said fire box; drain pipes through said insulating wall extending inward and downward; a lower smoke chamber between the minor segment of said lower tube sheet and the oblique section of said fire box; up-draft tubes fixed in said upper tube sheet and said major segment of said lower tube sheet, and down-draft tubes fixed in said upper tube sheet andsaid minor segment of said lower tube sheet; an insulated shell, having its in said upper tube sheet and the major segment of said lower tube sheet, in damper-controlled communication with said upper smoke chamber and in open communication With said fire box; a conduit, having a flange with a plurality of holes therein, disposed within said insulated shell and spaced therefrom; and an annular damper, having a plurality of holes therein, supported movably on said flange.

' draft tubes xed in the front and sides and to a chord at the back, vertically disposed Within said shell and spaced therefrom, said wall comprising concentric shells and insulating material therebetween, the outer shell thereof being secured to the chord of the minor segment of said lower tube sheet and to the bottom of said main shell, and the inner shell mounted on the outer shell of said fire box; drain pipes through said insulating wall, extending inward and downward; 'a lower smoke chamber between the minor segment of said lower tube sheet and the obli ue section of said fire box; up-draft tubes fixed in said upper tube sheet and said major segment of said lower tube sheet, and downsaid upper tube sheet and said minor segment of said lower tube sheet; an insulated shell, having its ends fixed in said upper tube sheet and the major segment of said lower tube sheet, in dampercontrolled communication with said upper smoke chamber and in open communication with said fire box; a conduit, having a flange with a plurality of holes,y therein, disposed within said insulated shell and spaced therefrom; a fuel intake mounted in said conduit to form an annular chamber; a reservoir; a valve-controlled jacketed pipe leading from said chamber into said reservoir; a, fixed conical grate mounted in said fire box and a movable annular grate surrounding the base of said conical grate an annular perforated pipe disposed beneath said annular grate, and a suction blower in communication with said reservoir and said annular pipe.

OLIVER S. BOWMAN. 

